In a conventional electric power steering control apparatus, a command value of an assist torque, which is output to an AC motor, is determined by a current value on the q-axis (hereafter called q-axis current command value), and a current value on the d-axis (hereafter called d-axis current command value) based on the weak field control of the AC motor, in order to improve the follow-up performance of the steering wheel during high-speed steering.
When predetermined conditions are established and the q-axis current command value must be limited, the conventional electric power steering control apparatus limits not only the q-axis current command value, but also limits the d-axis current command value at the same rate as the case of limiting the q-axis current command value in order to improve the sensation of steering (e.g. see PTL 1).